Re: Fans (cpu/case) run 1 second then cut off, computer won't start.

Suggest you try the original configuration, and limit the PSU to less than 650W.

What was the condition/status of the original PSU rear light turn when the fans quit?

I am a volunteer. I am not an HP employee.To say THANK YOU, press the "thumbs up symbol" to render a KUDO. Please click Accept as Solution, if your problem is solved. You can render both Solution and KUDO.

The Law of Effect states that positive reinforcement increases the probability of a behavior being repeated. (B.F.Skinner). You toss me KUDO and/or Solution, and I perform better.

Re: Fans (cpu/case) run 1 second then cut off, computer won't start.

I'm checking with a friend who may have a MB these CPU will fit in to see if they're working OK,

and maybe a CPU that is known to be working to try in these two MB,

That's about the only way I have of checking the MB and CPUs.

I've made a visual check of all Capacitors, none seems to have "blown their top".

I may not have made it clear in my first post, but the fans start to spin as soon as the power is applied to the PS, and this is without anything connected to the MB, not even the on/off switch, but they still spin for a second or so.

I don't know if this is a characteristic of all AMD MB, or a symptom of the problem.

If it was just a voltage surge to charge up the capacitors, then cut off, I could under stand it,

I mounted the old MB/CPU in another case but got the same results.

Personally, I'm as Intel man myself, and have a wide varity of intel MB/Sockets to check most of their products,

I've never liked AMD, and finding more justification for that everyday.

I appreciate the suggestions and help, if you have any other suggestion, I'd appreciate them too, I've ran out. LOL

When I do find the problem, and I will, sooner or later, I'll come back and let everyone know, I'd hate to see anyone else in this predicament.